BINGHAMTON, N.Y — Even if police officers had immediately entered the immigrant center where a gunman had just shot down 13 people, the victims' injuries were so severe that none would have survived, a county prosecutor said Sunday.

The shooting at the American Civic Association stopped shortly after the first 911 calls came in at 10:30 a.m. Friday, but police didn't enter the building until nearly 45 minutes later.

Survivors reported huddling for hours in a basement, not knowing whether they were still in danger after the gunman, 41-year-old Jiverly Wong, killed 13 people.

Medical examiners who conducted autopsies reported that the victims' injuries were so severe they would not have survived, Broome County District Attorney Gerald F. Mollen said.

"We definitively can say nobody was shot after police arrival, and nobody who had been shot could have been saved even if the police had walked in the door within the first minute," Mollen said.

The prosecutor's comments came at a news conference Sunday, an hour before officials released a list of names and home countries of the victims.

Four Chinese were among those killed, and a Chinese student was also shot in the arm and leg but survived, officials said. The other victims came from Haiti, Pakistan, the Philippines, Iraq, Brazil, Vietnam and the United States.

The first 911 calls came in at 10:30 a.m., police Chief Joseph Zikuski said at a news conference. The callers spoke broken English, and it took dispatchers 2 minutes to sort out what was happening, he said.

Patrol officers arrived at 10:33 a.m., five minutes before a wounded receptionist called police to report a gunman in the building, Zikuski said. Police had earlier said it was that call that brought them to the immigration center.

When police arrived at the scene, the gunfire had stopped, so they believed there was no "active gunman" in the center and decided to wait for the SWAT team to arrive, Zikuski said.

The SWAT team entered the building until 11:13 a.m., 43 minutes after the first call to police.

"I'm not sure why they wouldn't have gone in there if the shooting was already done," said Kent Moyer, president of California-based World Protection Group, which offers protection services for corporate, commercial, industrial, entertainment, residential and retail clients. "What is happening all across the board in law enforcement is they've switched the tactic. They're not relying on waiting until the SWAT team gets there."

Moyer said many law-enforcement agencies conduct rapid-response training where the uniformed patrol officers are taught that "once they have sufficient backup, that they go in prior to the SWAT team getting there."

Zikuski contrasted the scene with the 1999 Columbine High School shooting in Colorado, in which 15 people died, including the two teenage gunmen. There, he said, it would have been better for police to enter the building as quickly as possible since it was obvious the gunmen were still alive and shooting.

"At Columbine, there were numerous shots ringing out and law enforcement stood by," he said. "I was, quite frankly, horrified when I knew that."

Pressed on why police didn't go into the building, Zikuski said information they were getting from the receptionist—specifically whether Wong was still alive—was uncertain enough to warrant caution. And unlike Columbine, police in Binghamton could be more deliberate because the gunman had stopped firing by the time they arrived.

"He was dead. We didn't know it," Zikuski said. "If there's a bunch of cops laying on the floor shot trying to rescue somebody else, it's not going to help anybody. All I can tell you is that we did what was expected and was the right thing to do under the circumstances. We did the right thing."

Zikuski said his officers would have gone into the building if shots had still been flying.

"If you arrive on the scene—the first two to four guys—and there's an active shooter, they enter," he said.

That is standard protocol today.

"Most law enforcement agencies have already changed their policies," Moyer said. "Obviously, that's something the state has to re-evaluate whether what they did was effective or not."

When reporters repeated the line of questioning on timing, Mollen jumped in to defend the police chief, a 30-year veteran of the force who has served as interim chief three times in the past 15 years.

"I don't think it's fair to ask Chief Zikuski to respond to hypotheticals," Mollen said, adding that there would be a full review and report on the shooting, including the police response.

A former FBI agent who was also a member of a SWAT team said the response was appropriate.

"Lord, that seems like that was fast," said Harold Copus, who now runs a consulting company based in Atlanta. "When something like this happens, as you can imagine, it's mass confusion."

Wong was "an avid gunman" who had recently visited a firing range weekly, Zikuski said, but authorities still don't know his motive.

Authorities don't know whether he had a particular target, and Zikuski said the choice of targets may have been random.

Officials have said Wong was apparently upset about losing his job at a vacuum plant and about people picking on him for his limited English.

A timeline of police response to NY shootings

Binghamton police Chief Joseph Zikuski gave the following timeline of the police response to the shootings at the American Civic Association on Friday:

10:30 a.m. - Broome County communications center received several 911 calls. The callers spoke broken English, and police at first couldn't determine the problem or the origin of the calls.

10:32 a.m. - Officers were dispatched to the scene.

10:33 a.m. - One of the police units radioed that they were at the scene.

10:38 a.m. - Police received a call from receptionist Shirley DeLucia, who had been shot but crawled under the desk with a cell phone. She gave police a description of the scene and the gunman.

11:13 a.m. - A SWAT team arrived and entered the building. Shortly afterward, they evacuated the surviving victims.

11:27 a.m. - Police reported that they had found DeLucia and took her out of the building.

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